diff --git a/tools/src/icon4pytools/liskov/parsing/validation.py b/tools/src/icon4pytools/liskov/parsing/validation.py
index afe67d7bd8..a6e4e8175f 100644
--- a/tools/src/icon4pytools/liskov/parsing/validation.py
+++ b/tools/src/icon4pytools/liskov/parsing/validation.py
@@ -41,7 +41,7 @@ def validate(self, directives: Sequence[ts.ParsedDirective]) -> None:
 
 
 def _extract_arg_from_directive(directive: str, arg: str) -> str:
-    match = re.search(f"{arg}=([^;)]+)", directive)
+    match = re.search(f"{arg}\s*=\s*([^\s;)]+)", directive)
     if match:
         return match.group(1)
     else: